Feed the world

With the global population projected to hit nine billion before 2050, agricultural scientists are calling for a new Green Revolution to feed all of those extra mouths. But can science and technology work the same miracles and raise crop yields in time, or will climate change prove to be agriculture’s undoing?

Humans have always made the soil work hard, but with the global population set to increase from its current–and almost incomprehensible–6.8 billion to a mind-boggling 9.1 billion in 2050, we’re about to make it work harder than ever. That prediction, by the UN’s Food and Agriculture Organization (FAO), represents a 34 per cent increase, and feeding all of those extra mouths would seem to be, at first glance, a Herculean task.

  • And it looks even less attainable when you consider that we can’t even feed our present population: last year, says the FAO, the number of chronically undernourished people–those who are unable to satisfy their basic needs in terms of food energy–passed the one billion mark, up from 842 million at the beginning of the 1990s.
  • Right now, across East Africa, more than 23 million people face critical food shortages following successive years of failed rains and worsening drought. Rice stocks held by the five major exporters recently fell from 30 million tonnes to 20 million tonnes; the international price of wheat rose by 75 per cent in 2007. The rocketing prices of almost all major food and feed commodities that year saw an additional 40 million people in Asia and the Pacific, and 22 million in sub-Saharan Africa, classified as undernourished.

‘We are not doing very well at all in feeding people,’ says Dr Keith Wiebe, deputy director of the FAO’s Agricultural Development Economics Division. ‘There had been progress towards reducing hunger, but it has gone into reverse in the past couple of years with price hikes and the recession. Biofuels are one of a number of significant factors, but we’ve seen poor harvests, high oil prices and increasing demand from China and India.’

It looks as though attempts to feed us all will merely determine the most efficient way to saw off the tree branch on which we’re standing. Yet many observers–including Wiebe–are optimistic, pointing out that food production continues to outpace population growth. While the global population has risen from three billion in 1960 to almost seven billion in 2009, the Royal Society calculates that for each person alive today, there is, in theory, an additional 29 per cent more food compared with 1960. FAO gross worldfood production (cereals, coarse grains, roots and tubers, pulses and oil crops) has grown from 1.84 billion tonnes in 1961 to 4.38 billion tonnes in 2007.

This has been achieved without an enormous expansion of land use. The total agricultural area has increased 11 per cent since the 1960s to 4.93 billion hectares, and arable area by nine per cent to 1.41 billion hectares. Today, just 150 crops are cultivated, a sharp drop from the 10,000 estimated by the Worldwatch Institute to have been employed historically, and three grains–maize, rice, and wheat–combined with potatoes, provide more than half of human energy needs.

  • Cereal yields can often be relatively easily improved with existing varieties of grain and with known practices, says the FAO. In Africa, they stand at around 1.2 tonnes per hectare, compared to an average yield of three tonnes per hectare in the developing world as a whole. To give one example, Senegal depends on imports for half of its food, but could not only be self sufficient but could potentially become a food exporter.


There are many reasons for the ills that plague global food production. Farmers often lack sufficient incentives or training to adopt yield-enhancing seeds or cropping techniques; countries with a surplus often export food and sell it at below cost, putting local farmers out of business; there’s a shrinking rural workforce, turning food producers into urban food consumers; the costs of agricultural inputs and energy are rising; and water scarcity is an increasing concern.

Biofuels, as Wiebe points out, are another emerging area of disquiet: grain production for biofuels increased by more than five per cent in 2008 to 120 million tonnes, according to the Worldwatch Institute, an almost ten per cent increase over the previous year. The FAO reports that continued rapid expansion of biofuel production up to 2050 would lead to three million more pre-school children in Africa and 1.7 million in South Asia being undernourished than would otherwise have been the case.

  • The withdrawal of state support for food production since the 1960s has been one of the most influential factors, according to Fred Mousseau, humanitarian policy advisor at Oxfam GB. ‘Governments sort of forgot about producing agriculture and bought cheapfood on international markets,’ he says. ‘There was little investment in small-scale farmers, herders, pastoralists. It hasn’t really worked. The private sector hasn’t filled the gap left by the state in the way that the World Bank expected.’
  • Perhaps the ugliest manifestation of rising concerns over food security has been the emergence of the land grab. Nearly 2.5 million hectares of farmland, generally arable but fallow, in five sub-Saharan countries–Ethiopia, Ghana, Madagascar, Mali and Sudan–have been bought or rented in the past five years at a total cost of US$920million, according to a report by the International Fund for Agricultural Development, the FAO and the International Institute for Environment and Development. In Ethiopia, India invested US$4billion in agriculture, including flower-growing and sugar estates; in Sudan, Saudi Arabia leased 10,000 hectares for wheat, vegetables, and livestock. Meanwhile, China acquired the rights to grow palm oil on 2.8 million hectares of Congolese land, and in Kenya, Qatar leased 20,000 hectares for fruit and vegetable cultivation in exchange for funding a US$2.3billion port.


So how much more food and land will we need in 2050? The FAO says that overall food production will need to increase by 70 per cent; annual cereal production will need to rise to about three billion tonnes from 2.1 billion tonnes today; and annual meat production will need to increase by more than 200 million tonnes to 470 million tonnes.

According to the FAO, the world has considerable land reserves that could, in theory, be converted to arable land. Currently, about 15 million square kilometres, roughly ten per cent the total land surface, is covered by cropland. The FAO projects that by 2050, the area of arable land will be expanded by 70 million hectares, or about five per cent, with land in developing countries expanding by 120 million hectares and arable land in developed nations contracting by 50 million hectares.

These figures are likely to rise as more people become better off and eat more meat, and land is set aside for biofuels. These changing consumption patterns, the impacts of climate change and the growing scarcity of water and land led John Beddington, the UK government’s chief scientific advisor, to describe the future global confluence of food, water and energy insecurity as a ‘perfect storm’.

  • Most scenarios of how climate change will affect our efforts to feed ourselves appear grim: salt water from rising sea levels affecting paddy fields; unpredictable climate with unreliable rainfall patterns harming seasonal farming practices; extreme weather damaging crops; and an increase in pests and disease. The FAO also reports that sub-Saharan Africa’s share of the world’s hungry people could rise from 24 per cent to up to 50 per cent. ‘The detrimental effects of climate change could reduce global crop production by almost ten per cent by 2050,’ says Stefanie Rost of the Potsdam Institute for Climate Impact Research (PIK).

  • Yet the picture is, perhaps unexpectedly, more mixed: the International Panel on Climate Change projects that global foodproduction could rise if local average temperatures increase by up to 3[degrees]C; any warmer and it could decrease. There may also be beneficial effects on plant growth from the rising levels of atmospheric carbon dioxide. And a report published late last year by the International Livestock Research Institute (ILRI) suggested that in East Africa, the effects of climate change on maize and bean harvests would see moderate declines across the region, but some agricultural areas would do better than others. In the mixed crop-livestock systems of the tropical highlands, the study suggested that rising temperatures may actually favour foodcrops, helping to boost output of maize by about half in highland ‘breadbasket’ areas of Kenya and beans in similar parts of Tanzania. However, harvests of maize and beans could decrease in more humid areas, and across the entire region, production of both crops is projected to decline significantly in dry lands.

Carlos Sere, director general of the ILRI, has an optimistic interpretation. ‘The emerging scenario of climate-change winners and losers isn’t inevitable,’ he says. ‘Despite an expected threefold increase in food demand by 2050, East Africa can still deliver foodsecurity for all through a smart approach that carefully matches policies and technologies to the needs and opportunities of particular areas.’


But if we get it wrong, hunger won’t be the only consequence. In 2007, food riots broke out in Mexico as corn prices rose after the USA began to divert the crop to produce ethanol. Dissatisfaction at the way in which global food production is organised has crystallised into the Via Campesina, an international peasant movement that originated in the 1990s but has gained impetus from recent rises in food prices. Today, it represents farmers in 56 countries, including an organisation of Scottish crofters. The movement talks of food sovereignty rather than food security, by which its leaders seek to organise food production and consumption according to the needs of local communities, giving priority to production for local consumption.

A fundamental tenet of Via Campesina is that peasant or family-farm agriculture is based on sustainable production with local resources and in harmony with local culture and traditions. This approach has increasing sympathy and support among manyfood scientists, who endorse what is described as an agro-ecological approach to food production. This involves mixing varieties of crops, polycultures and crop-livestock combinations whose sustainability is underpinned by the use of local energy, material and labour resources, and species diversity.

  • ‘The same key principles underlie the sustainability of these farms,’ says Professor Miguel Altieri, an agro-ecologist at the University of California, Berkeley. ‘Farmers who live in rural communities near cities and towns, and are linked to local markets, avoid the energy wasted and gas emissions associated with transporting food hundreds and even thousands of kilometres.’
  • Altieri argues that the world already has enough land and food to feed nine billion people, but that the present top-down approach to agriculture prevents this from happening. ‘The problem is political,’ he says. ‘If you want to solve the problem, you instigate land reform, giving land to small farms. The trouble is that research organisations are supporters of genetic selection because they are all plant breeders. In the 1960s, the food movement was driven by a pesticides treadmill; today it’s being driven by a transgenics treadmill.’

But Altieri stresses that he’s no Luddite. ‘We have a dialogue between science and the traditional knowledge of farmers who have been farming for thousands of years,’ he says. ‘Diversity is the key. It’s an agricultural model that decouples us from a dependence on pesticides and provides resilience to climate change.’

The view is endorsed by the UK-based Food Ethics Council (FEC), which argues that too much emphasis is placed on growingfood, as opposed to how it’s distributed and consumed. ‘Instead of asking, “How can science and technology help secure globalfood supplies?”, we need to ask, “What can be done–by scientists but also by others–to help the world’s hungry?”,’ says Dr Tom MacMillan, the council’s executive director.

  • The FEC isn’t alone. The International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD), a UN-backed study written by 400 scientists and approved by 60 governments, including that of the UK, cites the failure of many developed nations to consider social and environmental needs when trying to meet agricultural production goals. Instead, IAASTD argues that the key is to combine science and technology research with traditional knowledge to provide local solutions.
  • The FAO’s Wiebe also favours this approach. ‘It’s unfortunate the debate between agro-ecology and science has become so polarised,’ he says. ‘Neither by themselves will be sufficient. There’s going to be a mix of solutions, most of them site-specific. The important thing is to be open to both knowledge of farmers and modern science.’

DFID, the UK government’s international aid department, has begun to make funding for some projects conditional on scientists consulting local communities, and Britain’s Royal Society believes crop researchers should undergo placements in developing nations. ‘You need to link scientists to the ultimate end users,’ says Dr James Smith, co-director of the Centre of African Studies and ESRC Innogen Centre at the University of Edinburgh. ‘You get everybody involved and think how it will translate from the field lab into farming.’

‘A lot of the debate about technology shouldn’t be about the technologies themselves but about their application,’ says Oxfam GB’s Mousseau. ‘How do we save water, protect the fertility of the land? [Answering these questions] doesn’t require research institutes, it requires training of farmers on the ground.’ Mousseau points to the example of Ethiopian corn farmers. Thanks to government loans, in 2002, Ethiopia enjoyed its highest corn production for a decade. But with no system to help the farmers market the corn, there was no price control, the market collapsed and farmers sold at a loss. Many went bankrupt and ended up being recipients of UN food aid.


It’s clear, however, that new technologies will be needed to make up for shortfalls in land and farming skills, and many experts believe that new varieties of food staples, either developed by genetic modification or through plant breeding, are essential. Examples include salt-tolerant rice, drought-tolerant maize and heat-tolerant varieties of climbing beans.

Last autumn, the Royal Society published Reaping the Benefits, a report that called for 2billion [pounds sterling] to be invested in new technologies to address global food security. The society said that agro-ecology had a role to play, but that in the medium term, genetic modification and breeding of new varieties of crops that are resistant to disease, drought, salinity, heat and toxic heavy metals was essential. The longer term aim, the society said, is the development of nitrogen-fixing cereals, which would require less fertiliser, and perennial crops.

Yet some observers are concerned that those seeking to alleviate hunger can become too hamstrung by technology–and that technology risks becoming one-dimensional. Many of the innovations that will emerge are likely to come from the Consultative Group for International Agricultural Research, which has sought to centralise expertise and research into regional hubs to be disseminated around the world.

  • Technology is crucial, but is frequently not practically applied to local conditions, according to Smith, who feels that scientific research needs to become ore practical and tap into local knowledge more than it has done in the past. ‘We have a situation where centres are focusing on high-risk, high-gain programmes, rather than spreading risk and expertise around. It needs to be more subtle,’ he says. ‘It’s not clear to me that biofuels or GM crops will answer the problems.’
  • A reduction of water use will undoubtedly be central to many solutions. Irrigated agriculture covers one fifth of arable land and contributes nearly half of crop production, says the FAO. According to the PIK, without substantial improvements in water productivity or other measures to increase yields on present cropland, an expansion by about ten million square kilometres would be required to feed a population of ten billion. This would require an extra 4,500 cubic kilometres of water every year on top of the current 8,800 cubic kilometres used. ‘In many regions of the world that already face limits of water availability, that isn’t an option. We need to think of better ways to use the water that’s there,’ says Dieter Gerten, a hydrologist at the PIK.

Studies by the PIK looking at harvesting rainwater for use during dry spells and reducing soil evaporation found that such behaviour could increase global crop production by about 20 per cent, with the highest potential mainly in semi-arid regions such as the US Midwest, the Sahel, southern Africa, and central Asia.

WWF has pioneered a system of rice intensification that appears to increase yields and use less water–a potentially crucial development since half of the world depends on rice as a food staple, source of income, or both. Traditional farming requires up to 5,000 litres of water to produce one kilogram of rice; the WWF technique plants young, single seedlings around 25 centimetres apart, providing better airflow and access to sunlight than in conventional systems. Pilot projects in India show crop yields up from three tonnes to five tonnes per hectare, using 40 per cent less water.


Yet that finishing line, with the daunting target of feeding 9.1 billion people by 2050, looms ever larger. Smith feels that, unless significantly altered, the present system of crop research could fail to deliver. ‘The Green Revolution created new varieties of grains that worked in optimal conditions. With climate change, there may well not be optimal conditions,’ he says. ‘The reality is, we can’t feed everyone properly now. I suspect that there will always be one billion people or more who are malnourished or have insufficient calories.’

But Oxfam GB’s Mousseau argues that the goal is achievable–just. ‘It will require an increase in political will compared with what we’ve seen,’ he says. ‘It’s possible, but there has to be a recognition that this is about people’s right to food, rather than the interests of a few large corporations who are trying to guide the international agenda. There are successful examples: Indonesia and Brazil have both reversed the tide through proactive programmes in food and agriculture.’

Wiebe also believes the target is attainable. ‘I’m cautiously optimistic,’ he says. ‘That it’s a difficult challenge is illustrated by the fact that we’re nowhere near feeding everyone today. But it’s more a question of access to food than production. The resources are there. It requires policy choices and appropriate investment. These are big challenges, but the FAO thinks they can be met.’

The Green Revolution

The Green Revolution began in the 1960s, transforming agricultural practices and using technological innovation to breed hybrid varieties of cereal crops and significantly increase crop yields. Early examples included high-yielding hybrid Wheat in Mexico and hybrid varieties of rice in the Philippines.

The increases have been substantial. According to the FAO, between 1961 and 1985, yields of cereal crops such as wheat, rice and maize doubled in developing countries. But there were drawbacks. For the most part, food wasn’t grown where the need for it was most pressing. The Green Revolution was generally unable to significantly increase yields in more marginal areas and demanded that farmers engage in new and more intensive forms of agricultural production, in some cases dramatically altering their livelihoods and the risks they were obliged to take.

Where crop improvements were accompanied by investment in infrastructure, such as in parts of Asia and Latin America, there were widespread benefits. But the poorest farmers in Asia, and more particularly in Africa, lacked the resources to adopt the entire package of technologies. Yield increases varied, and were more successful in environments that most closely mirrored those of the research centres where the seeds were first developed.

The Green Revolution also concentrated investment in a series of international agricultural research centres, the Consultative Group for International Agricultural Research. ‘There’s a brain drain, where you see the local agricultural research programmes in developing countries being stripped of the best people,’ says Dr James Smith, co-director of the Centre of African Studies and ESRC Innogen Centre at the University of Edinburgh. ‘The big institutions take up the funds and local centres can’t compete.’

Technology meets tradition

The answers to improving yields don’t always–or even, perhaps, often–require multi-million-pound technological investment. In Kenya, the use of a so-called push-pull system of pest management devised by the International Centre for Insect Physiology and Ecology has increased maize yields by more than 100 per cent, and has now been adopted by more than 10,000 farmers there and in Uganda and Tanzania.

Maize is an important food and cash crop in East Africa, but it’s plagued by two moths: the spotted stem borer (below) and the maize stalk borer (bottom). The larvae of these moths can cause yield losses of up to 40 per cent.

The low-cost system removes the need for pesticides through the use of plant species that either ‘push’ away the pests or ‘pull’ them into ‘trap’ crops. First, the maize field is surrounded by a border of Napier grass, which is more attractive to the moths than maize (the ‘pull’ part of the system). The forage legume silverleaf is then planted within the maize. This releases semiochemicals that repel the stem borer moths (the ‘push’ element). Silverleaf also fixes atmospheric nitrogen, contributing to crop nutrition.

The Royal Society cites the push-pull system as a classic example of the combination of local knowledge with agro-ecology. Researchers are now looking to develop push-pull strategies for crops other than maize.

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